58 lines
1.4 KiB
JavaScript
58 lines
1.4 KiB
JavaScript
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"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.Queue = void 0;
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class Queue {
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/**
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* A really simple queue with concurrency.
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*
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* @param {Function} worker
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* @param {Object} options
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* @param {!number} options.concurrency
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*/
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constructor(worker, options = {}) {
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this._worker = worker;
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this._concurrency = options.concurrency || 1;
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this.tasks = [];
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this.total = 0;
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this.active = 0;
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}
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/**
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* Push a task to the queue.
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*
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* @param {T} item
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* @param {!Function} callback
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*/
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push(item, callback) {
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this.tasks.push({ item, callback });
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this.total++;
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this._next();
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}
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/**
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* Process next job in queue.
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*/
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_next() {
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if (this.active >= this._concurrency || !this.tasks.length) {
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return;
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}
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const { item, callback } = this.tasks.shift();
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let callbackCalled = false;
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this.active++;
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this._worker(item, (err, result) => {
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if (callbackCalled) {
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return;
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}
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this.active--;
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callbackCalled = true;
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callback === null || callback === void 0 ? void 0 : callback(err, result);
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this._next();
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});
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}
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/**
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* Stops processing queued jobs.
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*/
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die() {
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this.tasks = [];
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}
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}
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exports.Queue = Queue;
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//# sourceMappingURL=queue.js.map
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